Researchers have demonstrated the potential utility of microfluidics for cell biology and its ability to define the environment. However, the use of microfluidics by biologists is still the exception. With the potential benefits of microfluidics clear, why have microfluidic systems not found more widespread use in cancer research and drug screening applications? Cancer is a complex disease and research into the basic mechanisms of the disease could benefit greatly from the ability to explore more factors more quickly and to utilize functionality (e.g., defined co-culture, precise temporal/spatial environmental control) that is not possible in traditional well culture. We believe there exist several barriers preventing microfluidic culture systems from having a major impact on cancer biology (accessibility, relevance, biological model, efficiency/throughput). Our broad aim is to bridge the gap between the worlds of engineering and cancer biology by understanding the needs/limitations of current cell-based cancer biology research and then providing a technology platform well matched to those needs and capable of addressing emerging needs (e.g., co-culture, 3D culture). Our innovative platform merges simple microfluidic technology (e.g., passive pumping) with existing pipetting methods to provide a range of cell manipulation functionality capable of highly parallel operation. We propose to demonstrate the accessibilty/ease of use of the platform, achieve measureable outcomes in throughput, efficiency, accuracy and robustness, and utilize the system to study growth regulation of mammary epithelial cells. Specific experiments include operational robustness, cell seeding consistency and assay execution. The biological focus of this project will be an extensive 2016 datapoint study exploring the response of the NMuMG cell line and primary mouse mammary epithelial cells (normal or lacking Sdc-1) to a variety of growth factors (EGF, IGF, FGF, insulin, FGF+TGF(3, serum, WntSA) at different concentrations. In addition, we will demonstrate a novel liquid valve to control soluble factor interactions between two cell types to study EMT thresholds. As part of these studies, we will demonstrate a 25X reduction in the number of animals required for typical 24 well plate cell-based studies. [unreadable] [unreadable] [unreadable]